Terry Fator’s live show is getting to be a little like “The Muppet Show.” After five years, there’s no reason for him to behave as if we’re not as familiar with his puppet characters as we are with him.

It’s a mixed blessing. The Muppets were so popular they are still making movies. But the characters are more memorable than the actual jokes in any old TV episode. And that’s kind of how Fator’s show plays these days.

The ventriloquist recently celebrated his fifth anniversary at The Mirage, and the longer he stays in town, the more he feels the need not to repeat himself. Creative ambition and repeat customers go hand in hand, motivating him to change the show every year or so.

If you’re a hard-core fan, it’s variations on a theme you already love. And if you’re a first-timer, it’s all new to you.

It’s anyone who lands in the middle who might find the novelty wearing off, and with Fator it never should. His extraordinary ventriloquism skills are what landed him on that stage, but the extraordinary is becoming more ordinary over time.

Sure, there are a few moments when he jolts us back into the wonder of his vocal impressions, such as a cute girl puppet singing Adele’s “Skyfall.”

But more often, the new edition — same structure, new jokes — plays more like the disposable, late-night talk shows (or ’70s variety TV) that obviously inspire the star.

The theme of this year’s show is that the little turtle Winston decides to ditch Fator and go Hollywood. That means the overhead screens occasionally cut to Photoshop movie-poster puns, such as “Turtle Recall,” which remind us why Jay Leno got retired from “The Tonight Show.”

And Fator is determined to sing three original songs in his own voice. His voice is pleasant enough, and a maudlin song about a little boy who dies (“Horses in Heaven”) raises money for charity. Still, if you’ve found something in the world not many other people in the world can do, why spend three songs on something a lot of people do better?

One thing that has improved over five years is Fator’s ability to pack more show into less running time. He’s learned how to get all he needs from each character in seven or eight minutes, and how to put each one to a different comedic and musical use. Remember, variety TV was popular for a reason.

Here, the cowboy puppet Walter T. Airedale can run for president under the slogan “Are you better off than you were four beers ago?” and work in some topical humor. The suave black puppet Julius can get to the low-rent, Jeff Dunham-style racial jokes and even confuse Fator for Dunham. “All you people look alike to me,” he says.

By that he means all ventriloquists. Save the groan. At least the gay-stereotype puppet sat this show out.

A crash-test dummy named Wrex is good for pop-culture riffs on the Kardashians as well as singing an impressive medley about cars, with Fator’s versatile backing band covering everything from “Chitty Chitty Bang Bang” to “Low Rider.”

The stoner dude Duggie this time gets to pitch Fator on his weed-related entrepreneurial ideas, another bit that plays like a late-night talk show segment. At least this time, fans of this extended family will smile to learn Duggie is the son of another character.

And when Winston decides to come home again — did I spoil that? — the two crank up their Louis Armstrong and Kermit the Frog duet, “just like the old days.”

A call back to your own show five years ago? That’s an old-school definition of Las Vegas success if ever there was one. Fator has been able to kindle his own nostalgia, and didn’t even have to be around as long as the Muppets to do it.